During controlled ovarian hyperstimulation (COH), most of the early antral follicles are required to grow coordinately. Marked follicular size discrepancies during COH imply that an important number of follicles undergo unsatisfactory maturation. It has been proved that follicular priming with estradiol during the luteal phase of the cycle prior to COH or testosterone treatment during the early follicular phase of the COH cycle may increase the amount of oocytes and embryos retrieved. Nevertheless there are no prospective studies comparing such approaches. The present study consist of two phases: